package com.itheima.reggie.filter;


import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 过滤器检查用户是否完成登录
 */
@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    //路径匹配器
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        //1.获取本次请求的URI
        String requestURI = request.getRequestURI();

        //注意：
        //  @WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
        //      这里的/*是由tomcat解析，支持任意路径的匹配
        //  /backend/** 这里的通配符是由spring工具类 AntPathMatcher 解析
        //      /backend/* 里面的*代表的是一层目录任意
        //      /backend/** 里面的*代表的是多层目录任意   例如：/backend/page/login/login.html
        String[] urls = new String[]{
          "/employee/login",
          "/employee/logout",
          "/backend/**",
          "/front/**",
          "/common/*",
          "/user/login",
          "/user/sendMsg"
        };

        //2.判断本次请求是否需要处理
        log.info("本次请求为: {}",requestURI);
        boolean check = check(requestURI, urls);

        //3.如果不需要处理,则直接放行
        if (check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4.判断登录状态,已登录放行
        if(request.getSession().getAttribute("employee") != null){
            log.info("用户已登录,用户id为: {}",request.getSession().getAttribute("employee"));

            //登录成功将登录人id存储到ThreadLocal中
            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //4-2.判断登录状态,已登录放行
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录,用户id为: {}",request.getSession().getAttribute("user"));

            //登录成功将登录人id存储到ThreadLocal中
            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        //5.如果未登录则放回未登录结果
        log.info("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
        return;
    }

    /**
     * 检查此次请求是否需要放行
     * @param requestURI
     * @param urls
     * @return
     */
    public boolean check(String requestURI,String[] urls){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
